ADEN, Yemen, Jan. 10 (Xinhua) -- At least six soldiers of the internationally-backed Yemeni government were killed and several high-ranking military commanders injured in a strike launched by a Houthi drone in Yemen's southern province of Lahj on Thursday, a security official told Xinhua.

The Houthi rebels used an Iranian-made drone and shelled a military parade held for new army graduates at the Anad military air base in the government-controlled province of Lahj, the local security source said on condition of anonymity.

The High-ranking army commanders of Yemen's Defence Ministry and other government officials who attended the military parade were slightly injured by the Houthi attack, the source said.

He said that the army's Chief of Staff Abdullah Nakhi, his deputy Saleh Zindani, and Lahj Governor Ahmad Abdullah Turki were slightly injured and were moved immediately to neighboring province of Aden to receive treatment.

Director of Ibn Khaldoon Hospital in Lahj province told Xinhua that the drone attack resulted in the killing of six soldiers and injuring of 20 others.

He said that leader of Yemen's military intelligence agency Saleh Tamah was critically injured and was moved directly to Aden to receive urgent surgeries.

Major General Thabet Jawas, who leads the Anad military air base, appeared in a short footage, describing the attack as a botched attempt by the Houthi rebels to target the government's military leaders.

Jawas confirmed that all the senior army commanders are safe and the booby-trapped Houthi drone exploded meters from parade site.

"We are all ok. We are all fine. The Houthis drone was a botched attempt. They cannot accomplish anything. The military parade went on, no problem at all. We are winning," Jawas said in the footage revealed by local media outlets.

The Houthi-affiliated Masirah television network reported that the group's fighters launched the attack with a new Qasef-2 drone against the pro-government military parade in Lahj.

The Houthis said through their official media that the drone attack on the military parade in Lahj came as a "response to the continued raids of Saudi aggression, targeting of innocent citizens."

The largest military air base of Anad lies some 60 km north of Yemen's temporary capital of Aden city and witnessed several attacks by the Houthis including a missile attack last year.

The drone attack is likely to deal a blow towards a cease-fire in the port city of Hodeidah on the Red Sea coast where warring factions blamed each other for repeated violations that have been reported since the truce went into effect on Dec. 18, 2018.

The Houthis aligned with Iran launched a large military campaign and seized the capital Sanaa in late 2014, forcing Yemen's Hadi and his government to flee into the southern port city of Aden.

Subsequently, the pro-Houthi forces backed by armored vehicles attacked Aden and shelled Hadi's Republican Palace, leading him to escape again into exile in neighboring Saudi Arabia.

Saudi Arabia with other Arab countries intervened militarily and began pounding the Houthi-controlled capital Sanaa in March 2015 in response to an official public request from Hadi to protect Yemen and roll back Iran's influence.

The internal military conflict between the Iranian-backed Houthis and the Saudi-backed Yemeni government recently entered its fourth year, aggravating the suffering of Yemenis and deepening the world's worst humanitarian crisis in the country.

The ongoing fighting between the two warring rivals with daily Saudi-led airstrikes plunged the most impoverished Arab country in the Middle East into more chaos and violence.

Three quarters of the population, or more than 22 million people, urgently require some form of humanitarian help, including 8.4 million people who struggle to find their next meal.